Is there a problem here?

[DWS]

After many years hiatus I am growing again. Problem, two of the seven plants shown here are turning yellow at the top and I am asking for help to ascertain what is happening.

 

[pute]

Hmmm. What is the temp of the leaves and how close are the plants to the light?

 

[DWS]

Hmmm. What is the temp of the leaves and how close are the plants to the light?

These are grown in a greenhouse.